Please comment to this post! (even a single letter would be great)!~

I haven’t posted something in ages. What was intended as a loosely-defined photography blog didn’t (yet) get beyond a single post about resolution and the empyness of megapixels as a measure of quality. Or maybe that was then*

So, I was left with the question: Is this blog still alive? Therefore – please just make a comment below if you caught this update on your online radar screen.

*Since I wrote my previous post it seems that the camera market actually reached some kind of a plateau, where most compact digital cameras settled for something between 10 and 14 megapixels. Digital SLR cameras are currently offering something between 12 and 20 megapixels, but this also seems to be stabilising. The focus is much more on ISO performance, image stabilisation, and (importantly) HD video. I see this as a encouraging development. Yay!

And remember the comment!

The Megapixel Race to nowhere

How many of you have seen adverts for digital cameras announcing “12 Megapixel sensor for unprecedented image quality” ? The number of megapixels is often the only thing people enquire about a new camera, and the higher the number, the more impressed they are. That, as well as how much it costs, how it looks, and how many times it can zoom.

While I also think that cost and looks are important, I think the “megapixel” (MP) race has reached ridiculous levels. A few years ago, when 2 MP cameras were the norm, more was indeed better. But that was then. In fact, that shiny new 12 megapixel compact camera you bought will almost certainly take worse pictures than your neighbour’s 6 megapixel digital SLR which he bought 4 years ago. Let me try to shed some light on the situation…

When looking at your photographs (on a computer monitor, high definition plasma TV, or prints), you won’t see the detail-advantage of a 12 MP photograph over a 6 MP photograph because:

• Your computer monitor can probably display somewhere between 1 and 2 MP
  (1920×1200 is pretty high-res, but still only 2.3MP)
• An A4-size print on photo paper has less than 9 MP resolution, and 13×18cm less than 4MP

There *are* differences between good and bad photographs, but it is not a function of megapixels:

• Your shiny National Geographic or Cosmopolitan magazines have limited resolution on a “full page” pic (probably < 5 MP), and yet those photographs look awesome!
• Pictures on facebook are only about 0.27 MP, and yet you can often see the difference between a good and a bad (e.g. cell phone) camera. This is mostly due to differences in dynamic range and the quality of the lens, not megapixel count!

Having more megapixels is actually often a disadvantage:

• A camera can only take pixel-level sharp pictures if the lens is able to form a sharp image on the sensor. The higher the pixel density, the sharper the lens needs to be. Very few cameras have lenses which can consistently provide detail to a sensor with 12 or more MP
• A sensor pixel can only hold a certain amount of charge before “overflowing”. The smaller the pixel, the less charge it can hold. This directly influences dynamic range (see images below)
• Every pixel needs light. Adding more pixels means each pixel will receive less light. This leads to “noisy” (speckled) images, since the camera needs to amplify the image signal more.
• The size of the sensor directly influences the price and size and weight of the camera, and therefore small cheap cameras invariably have small sensors. The only way to keep pixel density low is by keeping the number of megapixels reasonable.

Relative sizes of sensors used in most current digital cameras. (click for detail)

DPReview recently started listing the pixel density (MP/square cm) of all the cameras in their database. Because cameras have different size sensors the megapixel count on its own doesn’t tell you how densely they’re packed. Notice the enormous range in numbers! (a high pixel count combined with a low pixel density is best).

Camera Model	Price*	Pixel Count	Pixel Density
Kodak EasyShare C913	110 $	9.2 MP	37 MP/cm²
Canon PowerShot G9	500 $	12.1 MP	28 MP/cm²
Panasonic Lumix LX3	400 $	10.1 MP	24 MP/cm²
Panasonic Lumix G1	800 $	12.1 MP	5.0 MP/cm²
Canon EOS 50D	1400 $	15.0 MP	4.5 MP/cm²
Nikon D80	800 $	10.2 MP	2.7 MP/cm²
Sigma DP1	680 $	4.6 MP	1.6 MP/cm²
Nikon D3	4500 $	12.1 MP	1.4 MP/cm²

*prices (including a basic lens for DSLRs) based on Amazon.com quotes for November 2008

“Dynamic Range” is the ratio between the brightest and the darkest values a camera can record at the same time. Large pixels generally have more dynamic range than small pixels. And that is something you notice even on small pictures on facebook. Cell phone cameras are terrible in this regard.

Having an excessive pixel density can lead to images with “blown highlights”, where regions of the photo are overexposed (just white), or underexposed (just black).

A well exposed photograph taken with sufficient dynamic range (click for detail)	Blown highlights and underexposed shadows, due to low dynamic range (click for detail)

Also, since the signal from each pixel is weaker, it needs to be amplified more. Amplifying the signal also amplifies the noise, which leads to random speckles and reduced detail. The noise can be suppressed with “noise reduction”, but this blurs the image and removes even more detail!

Low-Noise Image (click for detail)	Noisy Image (click for detail)	Blurring due to “noise reduction” (click for detail)

One fact, however, is that an image file with more pixels will take up more of you hard drive space. So, with your new little camera you might just end up with huge files showing millions and millions of noisy, blurry pixels which can’t cope with the really dark or really bright pictures.

In fact, when comparing the brand new semi-professional Canon 50D (15MP) against its predecessor the 40D (which had 10MP), the DPreview team concluded: “in terms of per-pixel sharpness the 50D cannot quite keep up with the better 10 MP cameras on the market … It appears that Canon has reached the limit of what is sensible, in terms of megapixels … Considering the disadvantages that come with higher pixel densities such as diffraction issues, increased sensitivity towards camera shake, reduced dynamic range, reduced high ISO performance and the need to store, move and process larger amounts of data, one could be forgiven for coming to the conclusion that at this point the megapixel race should probably stop.“

Today’s new cameras can take better videos than ever before, have nice large displays, funky colours, are small and light, cost very little and can even detect faces and smiles. And these are all really cool. But we don’t need more megapixels for this!

To conclude: Beyond a certain point more pixels don’t improve picture quality – in fact, often the opposite. Sadly, it’s unlikely that manufacturers will stop the so-called “megapixel race” anytime soon. Why? Because numbers sell.

:-)

OK, so I’m just re-posting some news, but my blog has been dead for some time now. I thought I’ll let it reflect the fact that I’m still alive…

“Citizens of the Russian town Chelyabinsk calculated when the satellite, QuickBird, which takes images for Google Earth and Google Maps, would cross above their city and used people to make a giant smiley face. A rock concert on the main square attracted many people and everyone got a yellow cape. It looks like someone at Google was quicker than usual to put up the new data. Maybe Google likes the idea of an entire town working hard to get its 15 minutes of fame. The article has a screenshot of Google Maps and images taken directly at the event.”

Pretty cool, eh?

Re-form and reform

Thoughts on Werchter again… For me, one of the many* highlights was The Verve.

Recently, seemingly more than ever, it’s become the done thing for bands to re-form (and sometimes reform). Recent examples include: Ace of Base, Alice in Chains, All Saints, Atomic Kitten, Backstreet Boys, Genesis, Medadeth, The Police, Sex Pistols, Spice Girls and Stone Temple Pilots, to name a few. Worryingly, even Michael Jackson is said to be working on a new album, and I’ve seen his name on a poster of an upcoming festival…

That said, I was very impressed with The Verve’s performance. The old classics like Bittersweet Symphony, Sonnet, Lucky Man and The drugs don’t work were popular, but some of the most powerful stuff came from their upcoming album.

A personal favourite was the song “Sit and Wonder”, seen here at Coachella 2008:

It’s true that bands often sound better live than on a clinical recording, but let’s hope for the best!

*other amazing shows included The Chemical Brothers,
Neil Young, Radiohead, Sigur Rós, and even dEUS.

Moby killed my camera!

At Rock Werchter, on Friday 4 July 2008, a thin beam of intense green energy caused my 1-month old camera’s CCD sensor to have a stroke. Yes, dear readers, it’s true! Moby killed my camera. The high-powered(?) stage laser went straight into the lens, and – zap!

Here is what happened:

I thought cameras were designed to survive bright lights, but actions speak louder than words, and lasers shine brighter than than the brightest star.

Now, every picture I take with the camera looks exactly like this:

My camera now only sees this...

And now with a whacked camera, blasted ears and a stunned mind, I have also realised that this little blog has an existential crisis. In my opinion, successful blogs have a guiding theme or topic of interest – something this one has lacked thus far. That, and content. But now that will change… Over the coming weeks I’ll try to add more of the latter, so that the former might start to emerge. And I even made it a bit more pretty, by adding some eye candy to the to top bar… But then again, it’s only words, words, words.

Update: 15/07/2008

Indeed it seems as if things sometimes do go wrong at professional laser shows, as illuminated by the article in New Scientist entitled Party laser ‘blinds’ Russian ravers.
Ravers at the Aquamarine Open Air Festival in Kirzhach, 80 kilometres northeast of Moscow, began seeking medical help days after the show, complaining of eye and vision problems.

“They all have retinal burns, scarring is visible on them. Loss of vision in individual cases is as high as 80%, and regaining it is already impossible,” Kommersant quoted a treating ophthalmologist as saying.

Not cool.

Kan ons die rekening kry?

Ons almal weet wat aangaan in Zimbabwe, en elkeen maak maar ‘n grappie of skud sy kop daaroor. En so is dit ook dat ek weer vandag so ‘n foto in die pos gekry het.

Hierdie foto van 10 April 2008 kry ek by my oom, wat dit by vriende in Zim gekry het. 12 Miljoen Zim$ vir 6 mense se tweegang geregte en ‘n paar bottels bier by die plaaslike Mammas Mia’s. Tip ‘n mens nog10% in Zimbabwe?

‘n Carte Blance Video wys hoe die situasie gelyk het met inflasie van 1200% in Augustus 2006. Intussen het inflasie gestyg tot oor die 1 miljoen %, en ons kyk maar almal met morbiede fassinasie hoe die land verkrummel. Dis soos op TV – dis interessant om te sien hoe slegte dinge met ander mense gebeur.

So, kan ons die rekening kry?

Hello world!

It finally happened. After being inundated by, oh, it had to be literally two requests for me to start a blog, I succumbed. From this day onward the vast clutter of the world wide web will have one more little dust bunny, if you will.

Here you will find some thoughts, ramblings, things I like, things I think are important, and especially, the fruits of procrastination.

I will probably post in Afrikaans (sorry international ppl) alternating with English, depending on the topic and the mood. I will also link to some other worthwhile blogs, mostly of friends.

Instead of intermittently (whenever you’re procrastinating) checking to see how much I’ve procrastinated, I suggest using a “feed aggregator”, like the excellent Google Reader, or whichever one tickles your fancy.
Voila!